Today's work machines are employed in a number of machines used in industries such as manufacturing, mining, construction, and/or agriculture. These work machines generate a large amount of energy for performing a variety of tasks. Most work machines include a power source such as, for example, a diesel engine, a gasoline engine, a natural gas engine, or another appropriate power source that provides energy to complete a task. In certain work machines, the-power source is coupled to a motor that drives one or more mechanical devices that may perform a particular function associated with the power system.
Typically, these motors are operated under peak loading conditions for extended periods of time and, often, in extremely harsh environments. While these motors may be capable of operating under demanding conditions, the strain of continuous operation at peak loading can lead to damage to various components of the motor. For example, a sustained overload condition, if not properly monitored and/or controlled, may cause overheating of the conductive windings of the motor that could lead to permanent conductor damage and/or failure of the motor.
These motors may be protected from potential damage by monitoring and regulating the operation of the motor. One system, as described in U.S. Pat. No. 4,194,178 issued to Dumbeck (hereinafter referred to as “the '178 patent”) on Mar. 18, 1980, has been developed to monitor the load on a motor by measuring the shaft rotation of the motor and wirelessly transmitting the monitored data over the power windings of the motor by inducing an RF signal onto the power windings. The system of the '178 patent includes a detector and slip analysis circuit mounted within the motor housing, a modulator, and transmitter mounted within the motor housing that impress a modulated motor load signal of radio frequency onto the line that supplies power to the motor. A receiver outside the motor receives the modulated signal, and a demodulator transforms the received signal to produce the motor load signal. The system of the '178 patent also includes a corrective means to correct the motor load signal for variations caused by power line voltage fluctuations.
Although the system of the '178 patent may be capable of monitoring the operation of the motor over the power lines, this system may be unreliable. For example, because the monitoring system relies on current induction and indirect coupling methods for data transfer to wirelessly transmit data, as opposed to using direct electrical connections, the RF signals transferred over the power lines may be susceptible to electromagnetic interference, both internal and external to the motor. This interference may corrupt the monitored data, potentially resulting in unreadable or erroneous motor data.
Furthermore, the system of the '178 patent does not provide a continuous electrical connection capable of providing power to operate the motor. For example, because an induction method is used to wirelessly transfer the RF signals over the motor power windings, the system of the '178 patent is limited to output powers less than 100 milliwatts, which may be too low to energize the field windings of the motor enough to provide mechanical motion of the rotor.
In addition, because the system of the '178 patent does not provide a direct electrical connection to the motor, additional wiring harnesses and control systems are still required to operate the motor, which could substantially increase the manufacturing and production costs of the motor. Moreover, the inclusion of power wiring within the motor housing increases the risk of noise for the RF data monitoring link, which may result in further degradation of the RF signal quality and reliability.
The presently disclosed integrated motor monitoring system and method are directed toward overcoming one or more of the problems set forth above.